This invention relates generally to a slide rule-type of calculator for solving trigonometric problems. The term "slide rule" is meant to indicate that solutions to trigonometric problems can be found by manipulation of the various parts of the apparatus and solutions found by noting where on the scale in question various lines have intersected it.
Many types of mathematical problems can be solved either algebraically or graphically. Although algebraic techniques provide greater flexibility in the solution of general problems, graphical techniques offer distinct advantages in certain instances. For example, in the field of education, graphical approaches to problem solution are frequently more perceptable to the average student and therefore provide a more tangible understanding of the problem solved. Also, in certain instances, graphical solutions can be obtained more rapidly than algebraic solutions or can be used as a supplemental check thereof.
The usefulness of graphics is particularly significant in the science of trigonometry wherein problems involving the right triangle lend themselves readily to graphical solution. The angles and sides of right triangles can be measured very quickly and with very little effort. Consequently, various types of mechanical computers have been proposed for use in obtaining graphical solutions to trignometric problems. Devices of this type are disclosed, for example, in U.S. Pat. Nos. 3,014,646 and 3,414,190. Although generally useful for trignometric problems, these prior devices have exhibited various drawbacks such as being relatively costly, difficult to manipulate or interpret, etc.